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Error code reference

Samsung Air Conditioner Error Code OUTDOOR_YELLOW_GREEN_FLICKER

Heatsink sensor error

Samsung codesSamsung air conditioner codes

Heatsink sensor error

First step from the service manual

Check IPM module PIN#24,25 solder and short circuits

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What OUTDOOR_YELLOW_GREEN_FLICKER means on a Samsung air conditioner

The OUTDOOR_YELLOW_GREEN_FLICKER error on a Samsung air conditioner indicates a heatsink sensor error originating in the outdoor unit. The heatsink sensor monitors the temperature of the IPM (Intelligent Power Module), which controls the compressor inverter drive. When this sensor reports an out-of-range or implausible signal, the system triggers this fault code and displays it via the outdoor unit LED flickering in a yellow-green pattern. The IPM is a critical high-voltage component that regulates power delivery to the compressor motor, and accurate heatsink temperature feedback is essential to prevent thermal runaway or component damage.

The primary diagnostic entry point for this fault is the IPM module itself, specifically PIN numbers 24 and 25 on the IPM. These pins carry the heatsink sensor signal back to the main control board. Poor solder joints at these pins, which can develop due to thermal cycling over time, or short circuits between these pins or to adjacent conductors, are the leading causes of this error. A cold or cracked solder joint creates an intermittent or open-circuit signal, while a short can force the sensor reading to a fixed or erroneous value, both of which trigger the fault.

Beyond solder joint integrity, the heatsink thermistor itself can fail due to physical damage, contamination, or age-related drift in resistance characteristics. Wiring harness damage between the sensor and the IPM can also introduce resistance or intermittent continuity issues that mimic a sensor failure. Because this fault involves high-voltage inverter circuitry, all diagnostic work on the IPM and surrounding components should be performed with power fully disconnected and capacitors discharged.

Source: manufacturer service documentation.

Common causes of OUTDOOR_YELLOW_GREEN_FLICKER

  1. 01

    Poor or failed solder joints at IPM PIN 24 or 25

    Wiring / connection

    Thermal cycling over years of operation can cause cold or cracked solder joints at the heatsink sensor signal pins on the IPM module. Visually inspect and probe these joints for continuity issues.

  2. 02

    Short circuit at IPM PIN 24 or 25

    Wiring / connection

    A short between PIN 24 or 25 and adjacent conductors can force a fixed erroneous sensor value, triggering the fault. Check for solder bridges, debris, or damaged PCB traces in this area.

  3. 03

    Faulty heatsink thermistor

    Part replacement

    The heatsink temperature sensor itself may have failed due to age, moisture ingress, or physical damage, causing it to report an out-of-range resistance value. Testing the thermistor resistance against expected values will confirm this.

  4. 04

    Damaged wiring harness between sensor and IPM

    Part replacement

    Chafing, rodent damage, or connector corrosion in the harness connecting the heatsink sensor to the IPM can introduce resistance or open circuits that mimic sensor failure. Inspect the full harness run and connector pins.

  5. 05

    Failed IPM module

    Part replacement

    If solder joints, the thermistor, and wiring all check out correctly, the IPM module itself may have internal failure at the sensor input circuitry. Replacement of the IPM is required in this case.

See the test procedure for each cause

Frequently asked questions about OUTDOOR_YELLOW_GREEN_FLICKER

What does OUTDOOR_YELLOW_GREEN_FLICKER mean on a Samsung air_conditioner?
This error code indicates a heatsink sensor error in the outdoor unit. The heatsink sensor monitors the temperature of the IPM module, which drives the compressor. When the sensor signal is lost or reads an implausible value, the system faults out and displays this LED pattern to alert a technician. It is a protective shutdown designed to prevent damage to the inverter drive components.
Can I fix the OUTDOOR_YELLOW_GREEN_FLICKER error myself?
This fault requires working inside the outdoor unit near high-voltage inverter components, including the IPM module. The first diagnostic step involves inspecting solder joints at specific IPM pins, which requires electronics knowledge and proper safety precautions including full power disconnect and capacitor discharge. This repair is best handled by a qualified HVAC or appliance technician. A knowledgeable DIYer with electronics experience may be able to perform a visual inspection of the solder joints but should avoid probing live circuits.
Is it safe to run my Samsung air conditioner with the OUTDOOR_YELLOW_GREEN_FLICKER error?
No, the system will typically not operate normally once this fault is active, as it is a protective shutdown. Attempting to force operation with a compromised heatsink sensor defeats the thermal protection built into the IPM circuit, which could result in overheating and permanent damage to the inverter components or compressor. The unit should remain off until the fault is diagnosed and resolved.
How much does it cost to repair the OUTDOOR_YELLOW_GREEN_FLICKER error on a Samsung air conditioner?
Repair costs depend heavily on the root cause. If the issue is simply a failed solder joint that can be reflowed, labor costs may range from $80 to $200. If the heatsink thermistor requires replacement, parts and labor combined typically range from $100 to $300. Replacement of a failed IPM module is the most expensive scenario, with parts and labor potentially ranging from $300 to $700 or more depending on the unit model.
Will resetting my Samsung air conditioner clear the OUTDOOR_YELLOW_GREEN_FLICKER error?
A power reset may temporarily clear the fault code, but if the underlying hardware problem persists, the error will return once the system attempts to read the heatsink sensor again. Resetting without repairing the root cause does not fix the problem and could mask the issue temporarily. A proper diagnosis of the IPM PIN 24 and 25 solder joints, the thermistor, and the wiring harness is necessary to achieve a lasting resolution.

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